src/udev/net/link-config.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4  This file is part of systemd.
   5
   6  Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <netinet/ether.h>
  23 #include <linux/netdevice.h>
  24
  25 #include "sd-id128.h"
  26
  27 #include "missing.h"
  28 #include "link-config.h"
  29 #include "ethtool-util.h"
  30
  31 #include "libudev-private.h"
  32 #include "sd-rtnl.h"
  33 #include "util.h"
  34 #include "log.h"
  35 #include "strv.h"
  36 #include "path-util.h"
  37 #include "conf-parser.h"
  38 #include "conf-files.h"
  39 #include "fileio.h"
  40 #include "hashmap.h"
  41 #include "rtnl-util.h"
  42 #include "network-internal.h"
  43 #include "siphash24.h"
  44
  45 struct link_config_ctx {
  46         LIST_HEAD(link_config, links);
  47
  48         int ethtool_fd;
  49
  50         bool enable_name_policy;
  51
  52         sd_rtnl *rtnl;
  53
  54         usec_t link_dirs_ts_usec;
  55 };
  56
  57 static const char* const link_dirs[] = {
  58         "/etc/systemd/network",
  59         "/run/systemd/network",
  60         "/usr/lib/systemd/network",
  61 #ifdef HAVE_SPLIT_USR
  62         "/lib/systemd/network",
  63 #endif
  64         NULL};
  65
  66 DEFINE_TRIVIAL_CLEANUP_FUNC(link_config_ctx*, link_config_ctx_free);
  67 #define _cleanup_link_config_ctx_free_ _cleanup_(link_config_ctx_freep)
  68
  69 int link_config_ctx_new(link_config_ctx **ret) {
  70         _cleanup_link_config_ctx_free_ link_config_ctx *ctx = NULL;
  71
  72         if (!ret)
  73                 return -EINVAL;
  74
  75         ctx = new0(link_config_ctx, 1);
  76         if (!ctx)
  77                 return -ENOMEM;
  78
  79         LIST_HEAD_INIT(ctx->links);
  80
  81         ctx->ethtool_fd = -1;
  82
  83         ctx->enable_name_policy = true;
  84
  85         *ret = ctx;
  86         ctx = NULL;
  87
  88         return 0;
  89 }
  90
  91 static int link_config_ctx_connect(link_config_ctx *ctx) {
  92         int r;
  93
  94         if (ctx->ethtool_fd == -1) {
  95                 r = ethtool_connect(&ctx->ethtool_fd);
  96                 if (r < 0) {
  97                         log_warning("link_config: could not connect to ethtool: %s",
  98                                     strerror(-r));
  99                         return r;
 100                 }
 101         }
 102
 103         if (!ctx->rtnl) {
 104                 r = sd_rtnl_open(&ctx->rtnl, 0);
 105                 if (r < 0) {
 106                         log_warning("link_config: could not connect to rtnl: %s",
 107                                     strerror(-r));
 108                         return r;
 109                 }
 110         }
 111
 112         return 0;
 113 }
 114
 115 static void link_configs_free(link_config_ctx *ctx) {
 116         link_config *link, *link_next;
 117
 118         if (!ctx)
 119                 return;
 120
 121         LIST_FOREACH_SAFE(links, link, link_next, ctx->links) {
 122                 free(link->filename);
 123                 free(link->match_path);
 124                 free(link->match_driver);
 125                 free(link->match_type);
 126                 free(link->description);
 127                 free(link->alias);
 128                 free(link->name_policy);
 129
 130                 free(link);
 131         }
 132 }
 133
 134 void link_config_ctx_free(link_config_ctx *ctx) {
 135         if (!ctx)
 136                 return;
 137
 138         safe_close(ctx->ethtool_fd);
 139
 140         sd_rtnl_unref(ctx->rtnl);
 141
 142         link_configs_free(ctx);
 143
 144         free(ctx);
 145
 146         return;
 147 }
 148
 149 static int load_link(link_config_ctx *ctx, const char *filename) {
 150         _cleanup_free_ link_config *link = NULL;
 151         _cleanup_fclose_ FILE *file = NULL;
 152         int r;
 153
 154         assert(ctx);
 155         assert(filename);
 156
 157         file = fopen(filename, "re");
 158         if (!file) {
 159                 if (errno == ENOENT)
 160                         return 0;
 161                 else
 162                         return -errno;
 163         }
 164
 165         if (null_or_empty_fd(fileno(file))) {
 166                 log_debug("Skipping empty file: %s", filename);
 167                 return 0;
 168         }
 169
 170         link = new0(link_config, 1);
 171         if (!link)
 172                 return log_oom();
 173
 174         link->mac_policy = _MACPOLICY_INVALID;
 175         link->wol = _WOL_INVALID;
 176         link->duplex = _DUP_INVALID;
 177
 178         r = config_parse(NULL, filename, file,
 179                          "Match\0Link\0Ethernet\0",
 180                          config_item_perf_lookup, link_config_gperf_lookup,
 181                          false, false, true, link);
 182         if (r < 0)
 183                 return r;
 184         else
 185                 log_debug("Parsed configuration file %s", filename);
 186
 187         link->filename = strdup(filename);
 188
 189         LIST_PREPEND(links, ctx->links, link);
 190         link = NULL;
 191
 192         return 0;
 193 }
 194
 195 static bool enable_name_policy(void) {
 196         _cleanup_free_ char *line = NULL;
 197         const char *word, *state;
 198         int r;
 199         size_t l;
 200
 201         r = proc_cmdline(&line);
 202         if (r < 0)
 203                 log_warning("Failed to read /proc/cmdline, ignoring: %s",
 204                             strerror(-r));
 205         if (r <= 0)
 206                 return true;
 207
 208         FOREACH_WORD_QUOTED(word, l, line, state)
 209                 if (strneq(word, "net.ifnames=0", l))
 210                         return false;
 211
 212         return true;
 213 }
 214
 215 int link_config_load(link_config_ctx *ctx) {
 216         int r;
 217         _cleanup_strv_free_ char **files;
 218         char **f;
 219
 220         link_configs_free(ctx);
 221
 222         if (!enable_name_policy()) {
 223                 ctx->enable_name_policy = false;
 224                 log_info("Network interface NamePolicy= disabled on kernel commandline, ignoring.");
 225         }
 226
 227         /* update timestamp */
 228         paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, true);
 229
 230         r = conf_files_list_strv(&files, ".link", NULL, link_dirs);
 231         if (r < 0) {
 232                 log_error("failed to enumerate link files: %s", strerror(-r));
 233                 return r;
 234         }
 235
 236         STRV_FOREACH_BACKWARDS(f, files) {
 237                 r = load_link(ctx, *f);
 238                 if (r < 0)
 239                         return r;
 240         }
 241
 242         return 0;
 243 }
 244
 245 bool link_config_should_reload(link_config_ctx *ctx) {
 246         return paths_check_timestamp(link_dirs, &ctx->link_dirs_ts_usec, false);
 247 }
 248
 249 int link_config_get(link_config_ctx *ctx, struct udev_device *device,
 250                     link_config **ret) {
 251         link_config *link;
 252
 253         LIST_FOREACH(links, link, ctx->links) {
 254
 255                 if (net_match_config(link->match_mac, link->match_path, link->match_driver,
 256                                      link->match_type, NULL, link->match_host,
 257                                      link->match_virt, link->match_kernel, link->match_arch,
 258                                      ether_aton(udev_device_get_sysattr_value(device, "address")),
 259                                      udev_device_get_property_value(device, "ID_PATH"),
 260                                      udev_device_get_driver(udev_device_get_parent(device)),
 261                                      udev_device_get_property_value(device, "ID_NET_DRIVER"),
 262                                      udev_device_get_devtype(device),
 263                                      NULL)) {
 264                         log_debug("Config file %s applies to device %s",
 265                                   link->filename,
 266                                   udev_device_get_sysname(device));
 267                         *ret = link;
 268                         return 0;
 269                 }
 270         }
 271
 272         *ret = NULL;
 273
 274         return -ENOENT;
 275 }
 276
 277 static bool mac_is_random(struct udev_device *device) {
 278         const char *s;
 279         unsigned type;
 280         int r;
 281
 282         /* if we can't get the assign type, assume it is not random */
 283         s = udev_device_get_sysattr_value(device, "addr_assign_type");
 284         if (!s)
 285                 return false;
 286
 287         r = safe_atou(s, &type);
 288         if (r < 0)
 289                 return false;
 290
 291         return type == NET_ADDR_RANDOM;
 292 }
 293
 294 static bool should_rename(struct udev_device *device, bool respect_predictable) {
 295         const char *s;
 296         unsigned type;
 297         int r;
 298
 299         /* if we can't get the assgin type, assume we should rename */
 300         s = udev_device_get_sysattr_value(device, "name_assign_type");
 301         if (!s)
 302                 return true;
 303
 304         r = safe_atou(s, &type);
 305         if (r < 0)
 306                 return true;
 307
 308         switch (type) {
 309         case NET_NAME_USER:
 310         case NET_NAME_RENAMED:
 311                 /* these were already named by userspace, do not touch again */
 312                 return false;
 313         case NET_NAME_PREDICTABLE:
 314                 /* the kernel claims to have given a predictable name */
 315                 if (respect_predictable)
 316                         return false;
 317                 /* fall through */
 318         case NET_NAME_ENUM:
 319         default:
 320                 /* the name is known to be bad, or of an unknown type */
 321                 return true;
 322         }
 323 }
 324
 325 static int get_mac(struct udev_device *device, bool want_random,
 326                    struct ether_addr *mac) {
 327         int r;
 328
 329         if (want_random)
 330                 random_bytes(mac->ether_addr_octet, ETH_ALEN);
 331         else {
 332                 uint8_t result[8];
 333
 334                 r = net_get_unique_predictable_data(device, result);
 335                 if (r < 0)
 336                         return r;
 337
 338                 assert_cc(ETH_ALEN <= sizeof(result));
 339                 memcpy(mac->ether_addr_octet, result, ETH_ALEN);
 340         }
 341
 342         /* see eth_random_addr in the kernel */
 343         mac->ether_addr_octet[0] &= 0xfe;  /* clear multicast bit */
 344         mac->ether_addr_octet[0] |= 0x02;  /* set local assignment bit (IEEE802) */
 345
 346         return 0;
 347 }
 348
 349 int link_config_apply(link_config_ctx *ctx, link_config *config,
 350                       struct udev_device *device, const char **name) {
 351         const char *old_name;
 352         const char *new_name = NULL;
 353         struct ether_addr generated_mac;
 354         struct ether_addr *mac = NULL;
 355         bool respect_predictable = false;
 356         int r, ifindex;
 357
 358         assert(ctx);
 359         assert(config);
 360         assert(device);
 361         assert(name);
 362
 363         r = link_config_ctx_connect(ctx);
 364         if (r < 0)
 365                 return r;
 366
 367         old_name = udev_device_get_sysname(device);
 368         if (!old_name)
 369                 return -EINVAL;
 370
 371         r = ethtool_set_speed(ctx->ethtool_fd, old_name, config->speed / 1024,
 372                               config->duplex);
 373         if (r < 0)
 374                 log_warning("Could not set speed or duplex of %s to %u Mbps (%s): %s",
 375                             old_name, config->speed / 1024,
 376                             duplex_to_string(config->duplex), strerror(-r));
 377
 378         r = ethtool_set_wol(ctx->ethtool_fd, old_name, config->wol);
 379         if (r < 0)
 380                 log_warning("Could not set WakeOnLan of %s to %s: %s",
 381                             old_name, wol_to_string(config->wol), strerror(-r));
 382
 383         ifindex = udev_device_get_ifindex(device);
 384         if (ifindex <= 0) {
 385                 log_warning("Could not find ifindex");
 386                 return -ENODEV;
 387         }
 388
 389         if (ctx->enable_name_policy && config->name_policy) {
 390                 NamePolicy *policy;
 391
 392                 for (policy = config->name_policy;
 393                      !new_name && *policy != _NAMEPOLICY_INVALID; policy++) {
 394                         switch (*policy) {
 395                                 case NAMEPOLICY_KERNEL:
 396                                         respect_predictable = true;
 397                                         break;
 398                                 case NAMEPOLICY_DATABASE:
 399                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_FROM_DATABASE");
 400                                         break;
 401                                 case NAMEPOLICY_ONBOARD:
 402                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
 403                                         break;
 404                                 case NAMEPOLICY_SLOT:
 405                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_SLOT");
 406                                         break;
 407                                 case NAMEPOLICY_PATH:
 408                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_PATH");
 409                                         break;
 410                                 case NAMEPOLICY_MAC:
 411                                         new_name = udev_device_get_property_value(device, "ID_NET_NAME_MAC");
 412                                         break;
 413                                 default:
 414                                         break;
 415                         }
 416                 }
 417         }
 418
 419         if (should_rename(device, respect_predictable)) {
 420                 /* if not set by policy, fall back manually set name */
 421                 if (!new_name)
 422                         new_name = config->name;
 423         } else
 424                 new_name = NULL;
 425
 426         *name = new_name;
 427
 428         switch (config->mac_policy) {
 429                 case MACPOLICY_PERSISTENT:
 430                         if (mac_is_random(device)) {
 431                                 r = get_mac(device, false, &generated_mac);
 432                                 if (r == -ENOENT)
 433                                         break;
 434                                 else if (r < 0)
 435                                         return r;
 436                                 mac = &generated_mac;
 437                         }
 438                         break;
 439                 case MACPOLICY_RANDOM:
 440                         if (!mac_is_random(device)) {
 441                                 r = get_mac(device, true, &generated_mac);
 442                                 if (r == -ENOENT)
 443                                         break;
 444                                 else if (r < 0)
 445                                         return r;
 446                                 mac = &generated_mac;
 447                         }
 448                         break;
 449                 default:
 450                         mac = config->mac;
 451         }
 452
 453         r = rtnl_set_link_properties(ctx->rtnl, ifindex, config->alias, mac,
 454                                      config->mtu);
 455         if (r < 0) {
 456                 log_warning("Could not set Alias, MACAddress or MTU on %s: %s",
 457                             old_name, strerror(-r));
 458                 return r;
 459         }
 460
 461         return 0;
 462 }
 463
 464 int link_get_driver(link_config_ctx *ctx, struct udev_device *device, char **ret) {
 465         const char *name;
 466         char *driver;
 467         int r;
 468
 469         r = link_config_ctx_connect(ctx);
 470         if (r < 0)
 471                 return r;
 472
 473         name = udev_device_get_sysname(device);
 474         if (!name)
 475                 return -EINVAL;
 476
 477         r = ethtool_get_driver(ctx->ethtool_fd, name, &driver);
 478         if (r < 0)
 479                 return r;
 480
 481         *ret = driver;
 482         return 0;
 483 }
 484
 485 static const char* const mac_policy_table[_MACPOLICY_MAX] = {
 486         [MACPOLICY_PERSISTENT] = "persistent",
 487         [MACPOLICY_RANDOM] = "random"
 488 };
 489
 490 DEFINE_STRING_TABLE_LOOKUP(mac_policy, MACPolicy);
 491 DEFINE_CONFIG_PARSE_ENUM(config_parse_mac_policy, mac_policy, MACPolicy,
 492                          "Failed to parse MAC address policy");
 493
 494 static const char* const name_policy_table[_NAMEPOLICY_MAX] = {
 495         [NAMEPOLICY_KERNEL] = "kernel",
 496         [NAMEPOLICY_DATABASE] = "database",
 497         [NAMEPOLICY_ONBOARD] = "onboard",
 498         [NAMEPOLICY_SLOT] = "slot",
 499         [NAMEPOLICY_PATH] = "path",
 500         [NAMEPOLICY_MAC] = "mac"
 501 };
 502
 503 DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
 504 DEFINE_CONFIG_PARSE_ENUMV(config_parse_name_policy, name_policy, NamePolicy,
 505                           _NAMEPOLICY_INVALID,
 506                           "Failed to parse interface name policy");